Allegiant Air plans to offer year-round flights to the Tampa Bay region from Cincinnati/Northern Kentucky International Airport, the vacation airline announced Monday.

Limited weekly nonstop flights are scheduled to start May 15 to St. Pete-Clearwater International Airport in Clearwater, Fla.

Allegiant originally planned to offer the Sunday and Thursday flights to the Tampa Bay area from CVG only during the summer, but “we have seen such strong demand since we announced this route, we have reacted by adding more flights,” said Andrew C. Levy, president of Allegiant Air.

The Las Vegas-based airline is selling tickets to Tampa Bay through Oct. 28, and plans to announce its holiday-season schedule later this spring. Allegiant is offering an introductory, one-way fare for as low as $99. Those flights can only be booked on the company’s website, Allegiant.com.

Allegiant debuted at CVG in February with two flights a week to both Orlando, Fla., and the Fort Myers, Fla., region, and has already announced two expansions this month. Additionally, the airline plans to offer seasonal flights to Myrtle Beach from CVG beginning May 30 and ending Aug. 11.

CVG is the fastest-growing non-vacation city in Allegiant’s 15-year history.